Python/Json:Expecting property name enclosed in double quotes

I've been trying to figure out a good way to load JSON objects in Python. I send this json data:

{'http://example.org/about': {'http://purl.org/dc/terms/title': [{'type': 'literal', 'value': "Anna's Homepage"}]}}

to the backend where it will be received as a string then I used json.loads(data) to parse it.

But each time I got the same exception :

ValueError: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)

I googled it but nothing seems to work besides this solution json.loads(json.dumps(data)) which personally seems for me not that efficient since it accept any kind of data even the ones that are not in json format.

Any suggestions will be much appreciated.

This:

{
    'http://example.org/about': {
        'http://purl.org/dc/terms/title': [
            {'type': 'literal', 'value': "Anna's Homepage"}
        ]
     }
}

is not JSON.
This:

{
     "http://example.org/about": {
         "http://purl.org/dc/terms/title": [
             {"type": "literal", "value": "Anna's Homepage"}
          ]
      }
}

is JSON.

EDIT:
Some commenters suggested that the above is not enough.
JSON specification - RFC7159 states that a string begins and ends with quotation mark. That is ".
Single quoute ' has no semantic meaning in JSON and is allowed only inside a string.

as JSON only allows enclosing strings with double quotes you can manipulate the string like this:

str = str.replace("\'", "\"")

if your JSON holds escaped single-quotes (\') then you should use the more precise following code:

import re
p = re.compile('(?<!\\\\)\'')
str = p.sub('\"', str)

This will replace all occurrences of single quote with double quote in the JSON string str and in the latter case will not replace escaped single-quotes.

You can also use js-beautify which is less strict:

$ pip install jsbeautifier
$ js-beautify file.js

In my case, double quotes was not a problem.

Last comma gave me same error message.

{'a':{'b':c,}}
           ^

To remove this comma, I wrote some simple code.

import json

with open('a.json','r') as f:
    s = f.read()
    s = s.replace('\t','')
    s = s.replace('\n','')
    s = s.replace(',}','}')
    s = s.replace(',]',']')
    data = json.loads(s)

And this worked for me.

import ast

inpt = {'http://example.org/about': {'http://purl.org/dc/terms/title':
                                     [{'type': 'literal', 'value': "Anna's Homepage"}]}}

json_data = ast.literal_eval(json.dumps(inpt))

print(json_data)

this will solve the problem.

Solution 1 (Very Risky)

You can simply use python eval function.

parsed_json = eval(your_json)

Solution 2 (No Risk)

You can use ast library which is included in python by default, it also safely evaluate the expression.

import ast

parsed_json = ast.literal_eval(your_json)

Quite simply, that string is not valid JSON. As the error says, JSON documents need to use double quotes.

You need to fix the source of the data.

I've checked your JSON data

{'http://example.org/about': {'http://purl.org/dc/terms/title': [{'type': 'literal', 'value': "Anna's Homepage"}]}}

in http://jsonlint.com/ and the results were:

Error: Parse error on line 1:
{	'http://example.org/
--^
Expecting 'STRING', '}', got 'undefined'

modifying it to the following string solve the JSON error:

{
	"http://example.org/about": {
		"http://purl.org/dc/terms/title": [{
			"type": "literal",
			"value": "Anna's Homepage"
		}]
	}
}

JSON strings must use double quotes. The JSON python library enforces this so you are unable to load your string. Your data needs to look like this:

{"http://example.org/about": {"http://purl.org/dc/terms/title": [{"type": "literal", "value": "Anna's Homepage"}]}}

If that's not something you can do, you could use ast.literal_eval() instead of json.loads()

x = x.replace("'", '"')
j = json.loads(x)

Although this is the correct solution, but it may lead to quite a headache if there a JSON like this -

{'status': 'success', 'data': {'equity': {'enabled': True, 'net': 66706.14510000008, 'available': {'adhoc_margin': 0, 'cash': 1277252.56, 'opening_balance': 1277252.56, 'live_balance': 66706.14510000008, 'collateral': 249823.93, 'intraday_payin': 15000}, 'utilised': {'debits': 1475370.3449, 'exposure': 607729.3129, 'm2m_realised': 0, 'm2m_unrealised': -9033, 'option_premium': 0, 'payout': 0, 'span': 858608.032, 'holding_sales': 0, 'turnover': 0, 'liquid_collateral': 0, 'stock_collateral': 249823.93}}, 'commodity': {'enabled': True, 'net': 0, 'available': {'adhoc_margin': 0, 'cash': 0, 'opening_balance': 0, 'live_balance': 0, 'collateral': 0, 'intraday_payin': 0}, 'utilised': {'debits': 0, 'exposure': 0, 'm2m_realised': 0, 'm2m_unrealised': 0, 'option_premium': 0, 'payout': 0, 'span': 0, 'holding_sales': 0, 'turnover': 0, 'liquid_collateral': 0, 'stock_collateral': 0}}}}

Noticed that "True" value? Use this to make things are double checked for Booleans. This will cover those cases -

x = x.replace("'", '"').replace("True", '"True"').replace("False", '"False"').replace("null", '"null"')
j = json.loads(x)

Also, make sure you do not make

x = json.loads(x)

It has to be another variable.

As it clearly says in error, names should be enclosed in double quotes instead of single quotes. The string you pass is just not a valid JSON. It should look like

{"http://example.org/about": {"http://purl.org/dc/terms/title": [{"type": "literal", "value": "Anna's Homepage"}]}}

I used this method and managed to get the desired output. my script

x = "{'inner-temperature': 31.73, 'outer-temperature': 28.38, 'keys-value': 0}"

x = x.replace("'", '"')
j = json.loads(x)
print(j['keys-value'])

output

>>> 0

with open('input.json','r') as f:
    s = f.read()
    s = s.replace('\'','\"')
    data = json.loads(s)

This worked perfectly well for me. Thanks.

The below code snippet will help to transform data into JSON. All single-quotes should be converted into double-quotes to jsonify the data.

data = {
"http://example.org/about": {
    "http://purl.org/dc/terms/title": [{
        "type": "literal",
        "value": "Anna's Homepage"
    }]
}}
parsed_data = data.replace("'", '"')
data_json = json.loads(parsed_data)

I had similar problem . Two components communicating with each other was using a queue .

First component was not doing json.dumps before putting message to queue. So the JSON string generated by receiving component was in single quotes. This was causing error

 Expecting property name enclosed in double quotes

Adding json.dumps started creating correctly formatted JSON & solved issue.

As the other answers explain well the error occurs because of invalid quote characters passed to the json module.

In my case I continued to get the ValueError even after replacing ' with " in my string. What I finally realized was that some quote-like unicode symbols had found their way into my string:

 “  ”  ‛  ’  ‘  `  ´  ″  ′ 

To clean all of these you can just pass your string through a regular expression:

import re

raw_string = '{“key”:“value”}'

parsed_string = re.sub(r"[“|”|‛|’|‘|`|´|″|′|']", '"', my_string)

json_object = json.loads(parsed_string)

For anyone who wants a quick-fix, this simply replaces all single quotes with double quotes:

import json 

predictions = []

def get_top_k_predictions(predictions_path):
    '''load the predictions'''
    
    with open (predictions_path) as json_lines_file:
        for line in json_lines_file:
            predictions.append(json.loads(line.replace("'", "\"")))
            
    
get_top_k_predictions("/sh/sh-experiments/outputs/john/baseline_1000/test_predictions.jsonl")

You can use the json5 package https://pypi.org/project/json5/ instead of json package. This package can deal with single quotes. The decoding function is json5.loads(data) and similar to the json package.

If you are having a problem transform the dict to string and with double quote, this can help:

json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]')

json.loads documentation

The json syntax requires quotation marks for each "key" and "value". This makes it such a robust data format. In the following example I'm using colors and color as a key:

{"colors":[
  {
     "color":"red",
     "value":"#f00"
  },
  {
     "color":"green",
     "value":"#0f0"
  },
  {
     "color":"blue",
     "value":"#00f"
  },
  {
     "color":"cyan",
     "value":"#0ff"
  },
  {
     "color":"magenta",
     "value":"#f0f"
  },
  {
     "color":"yellow",
     "value":"#ff0"
  },
  {
     "color":"black",
     "value":"#000"
  }]}

If you want to convert a json string with single quotes to python dict use ast.literaleval()

>>> import ast
>>> payload = "{'hello': 'world'}"
>>> ast.literal_eval(payload)
{'hello': 'world'}
>>> type(ast.literal_eval(payload))
<class 'dict'>

This will convert the payload to a python dict.

I had the same problem and what I did is to replace the single quotes with the double one, but what was worse is the fact I had the same error when I had a comma for the last attribute of the json object. So I used regex in python to replace it before using the json.loads() function. (Be careful about the s at the end of "loads")

import re

with open("file.json", 'r') as f:
     s = f.read()
     correct_format = re.sub(", *\n *}", "}", s)
     data_json = json.loads(correct_format)

The used regex return each comma followed by a newline and "}", replacing it just with a "}".

I've had this error trying to normalize nested JSON column in Pandas. As noted by @Reihan_amn, replacing all single quotes with double quotes may affect the actual content. Therefore, when getting this error, you should replace only the ' that are where " should be in JSON syntax. You can do it with the following regular expression:

import re
import json

invalid_json = """{'http://example.org/about': {'http://purl.org/dc/terms/title': [{'type': 'literal', 'value': "Anna's Homepage"}]}}"""

valid_json = re.sub( "(?<={)\'|\'(?=})|(?<=\[)\'|\'(?=\])|\'(?=:)|(?<=: )\'|\'(?=,)|(?<=, )\'", "\"", invalid_json)

print(json.loads(valid_json))

This would suffice if the only problem was that there were single quotes (') in places were double quotes (") should be, in your original misformatted JSON document. But you would still get an error, if there are double quotes somewhere in your document that are also not part of JSON syntax. In this case I would suggest a 4 step-solution:

1. Replace all double quotes that are part of JSON syntax with single quotes (with the regex like above but ' and " swapped).

2. Replace all (leftover) double quotes with some special character that does not feature in your document, e.g. ``. You can do it with re.sub("\"", "``", x).

3. Replace all single quotes that are where the double quotes in JSON should be, with double quotes, using the regex given above.

You may now load JSON document and read it into a Pandas DataFrame with pd.json_normalize(df["json_col"].apply(json.loads)).

4. If you want, you can replace back all `` (or a special character of your choice) with ".

I would highly recommend usage of json prettify tools like JSON Prettifier for the same as it helped me fix the error of a trailing comma that I had in the JSON file, which yielded the same error.

My problem was that I copy and pasted a JSON snippet and the double quotes that were used were somehow a different, unrecognized double quote character. My file was valid JSON after replacing the double quotes.

Use the eval function.

It takes care of the discrepancy between single and double quotes.

It is always ideal to use the json.dumps() method. To get rid of this error, I used the following code

json.dumps(YOUR_DICT_STRING).replace("'", '"')

I have run into this problem multiple times when the JSON has been edited by hand. If someone was to delete something from the file without noticing it can throw the same error.

For instance, If your JSON last "}" is missing it will throw the same error.

So If you edit you file by hand make sure you format it like it is expected by the JSON decoder, otherwise you will run into the same problem.

Hope this helps!